Help for a family of 5

Hello- My wife and I will be visiting Switzerland with our three boys (ages 18,15, and 10) this June and I am thoroughly confused on what passes, cards, etc I should purchase if any. We are renting a car in Zurich and will travel to Lucerne and then onto Interlaken. In both places I hope, weather permitting, to travel up to Pilatus and the Jungfrau Mountains. We will then depart from Interlaken via train to Venice. Unfortunately we are only in Switzerland for 4 days. Should I purchase a pass in order to get discounts on the mountain railroads, boats, gondolas, etc or simply pay for the tickets individually? Will a Swiss Family Card help reduce the costs of those tickets for two of my kids and do I have to buy a pass to get the Family Card? Will the Family Card and/or Pass help me at all with the price of the tickets from Interlaken to Venice? Thanks in advance for any assistance.

Especially the Jungfrau railway is relatively expensive, so discounts add up pretty quickly and even out the costs of the pass (a return ticket Interlaken - Jungfrau currently costs CHF 186.20 per person). A Swiss Half Fare Card would be the pass for you. You need 3 of them: for the adults and the 18 year old. The other boys can travel along for free with a free Swiss Family Card. Please note that the Swiss Family Card cannot be used separately. It needs to be combined with one of the passes of the Swiss Travel System, such as the Swiss Half Fare Card. Please check our FAQ for more information about how to calculate which pass would be most economical.

The map we link to from the Swiss Half Fare Card page shows what discounts you'll get. The Swiss leg of the trip to Venice will be 50% discounted as well.